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Requirements of side curtain airbag have continued to increase. The revised SINCAP, FMVSS-226 ejection mitigation and small overlap of IIHS had added these requirements. To meet all the requirements, high inflator energy and complex cushion shape became necessary. Such situations increased possibility of cushion failure while deploying. Unfortunately, all the design verification tests are usually completed in a relatively latter stage of development and repetitive testing is needed to consider large dispersion of failure probability distribution. Therefore, verification and design improvement by numerical simulation in an early stage are desirable. A simulation method which can verify CAB deployment was developed in this study. The developed method has three distinct features. Firstly, nonlinear fabric materials and membrane finite elements are used to consider fracture of cushion fabric. Secondly, a pre-simulation procedure had been established.

The role of CAB is protecting the passenger's head during rollover and side crash accidents. However, the performance of HIC and ejection mitigation has trade-off relation, so analytical method to satisfy the HIC and ejection mitigation performance are required. In this study, 3 types of CAB were used for ejection mitigation analysis, drop tower analysis and SINCAP MDB analysis. Impactor which has 18kg mass is impacting the CAB as 20KPH velocity at six impact positions for ejection mitigation analysis. In drop tower analysis, impactor which has 9kg mass is impacting the CAB as 17.7KPH velocity. Acceleration value was derived by drop tower analysis and the tendency of HIC was estimated. Motion data of a vehicle structure was inserted to substructure model and the SID-IIS 5%ile female dummy was used for SINCAP MDB analysis. As a result, HIC and acceleration values were derived by MDB analysis.

The main role of CAB(side curtain airbag) is to protect the occupant's head in the event of side crash. The updated US NCAP for model year 2010 requires more extended coverage of CAB. It is not only required to cover the 50th%ile driver but also the 5th%ile driver and rear passenger. Although the general safety analysis model using only concerned sub-structure of the vehicle and prescribed structural motion is sufficient to handle frequent jobs, the analysis model with increased efficiency is needed when optimization is to be studied as it requires more runs and the model gets enlarged to consider extended sub-structure. In this study, three types of simplified analysis models are introduced. The first has an impactor which is composed of the head and neck with prescribed translational motions. It only uses the upper parts of the original sub-structure hence the run time is saved by 60∼70%.

Gas leakage properties in numerical models of a SAB (Side Air Bag) need to be estimated without any component testing for a prompt simulation. A reasonable and accurate method for predicting leakage properties, which can be used in MADYMO simulations, is introduced in this study. Leakage functions were formulated with 9 assumptions and coefficients of functions are obtained based on information about components of SABs. The Information and the obtained coefficients were collected as a database. 29 types of drop tower tests were done to build this database. Four types of SABs were chosen and tested to validate the accuracy of the developed prediction method. The resulting correlations between simulations and tests turned out to be sufficiently accurate.